This invention relates to polyurethanes derived from 1,4-lactones of 3,6-anhydro-2,3,4,5,6-pentahydroxyhexanoic acid. The polyurethanes of this invention are useful in coatings, compression moldings, control release systems, films, foams and the like.
Polyurethanes constitute a broad class of polymeric materials having a wide range of physical characteristics. The polymers are produced by the reaction of a polyisocyanate with a polyfunctional compound having an active hydrogen in its structure. This active hydrogen compound is generally a liquid or solid capable of being melted at relatively low temperatures. Most commonly, the active hydrogen compound contains hydroxyl groups as the moieties having the active hydrogen and thus are termed polyols, e.g., the polyols of polyesters, polyester amides, or polyethers, or mixtures of two or more such materials. For reasons of commercial availability and cost, the polyols most commonly employed in the preparation of polyurethanes are the polyethers having hydroxyl terminated chains and hydroxyl terminated polyesters.
The prior art active hydrogen compounds are derived from petroleum feedstocks. Such feedstocks are non-renewable resources which have become quite costly in recent years.
Active hydrogen compounds which are derived from renewable resources and which can be used in the manufacture of polyurethanes are needed.